@tig said:
To see the surface's edges you could use View > Hidden Geometry > ON
They'll then be visible but dotted, and the facets forming the surface become 'separate'.
Any smooth/soft/hidden edges can be seen dotted, and selected/edited etc...If you want them as solid edges...
To change them all to solid edges [with the setting View > Hidden Geometry > ON], use the Smooth tool [context-menu] and set the slider to minimum, all edges should turn to solid.
If some do not change the original author might have also 'hidden' them.
To fix those select all of the edges and context-menu > Unhide...
Now all edges should be solid, dividing the surface into its facets.
All smooth, soft and hidden behaviors having been removed
Thank you!